The Termite Infestation Map was developed by the US Forest Service years ago and was updated in the 1980s. The map is a depiction of the US Forest Service scientists’ estimate of various termite zones based upon the scientific studies conducted by the Forest Service. This is for subterranean termites only.

The original map was published as part of the US Government’s efforts to inform homeowners as to the dangers of termites and the signs of infestation. The publication used as called Home and Garden Bulletin 64, originally published in 1960, revised throughout the years with the 1994. The approximate termite hazards were listed as Region I: Very Heavy; Region II: Moderate to Heavy; Region III: Slight to Moderate; and Region IV: None to slight. Early maps did not include Hawaii and Alaska. Currently, Hawaii is in Region I and Alaska is in Region IV.

The map has not only been used in the publication but was used to establish Termite Infestation Probability Zones (TIP Zones). The US Department of Housing and Urban Development uses the TIP Zones to determine the risk and actions necessary as a requirement for guaranteeing mortgages. Conventional mortgage lenders, called mortgagees, also use the TIP Zones as their underwriting standards are usually similar to HUD’s.

The TIP Zones first noted by the US Forest Service have become an important part of determining whether inspection and prevention are underwriting requirements for mortgage loans. Finally, the International Code Council uses TIP Zones to determine building code requirements for termite prevention. The ICC’s International Residential Code (IRC) stipulates that code officials must use the map to determine building code requirements for subterranean termite prevention.

The type of termite which causes the most damage in North America is the subterranean termite. It is important to understand home danger zones for termites. These are areas more likely to be vulnerable to infestation by these termites. Homeowners who understand the home danger zones can take corrective action to reduce chances of infestation by termites.

Since the subterranean termites require ample moisture in order to thrive, areas of proven moisture are more hospitable to these termites. Couple that with a food source which contacts moist areas or the soil, and there are ideal conditions for infestation. In order to reduce the chance of infestation, homeowners can know the home danger zones for termites and can take corrective action so that conditions are not ideal for termites.

Probably the most common danger zone for termites is earth/wood contact. Some people call this moisture to wall contact. This condition is where non-pressure treated wood material is in direct contact with the soil. When this condition is present, there is adequate moisture, adequate food, and adequate protection for the termites. This is a condition conducive to termite infestation. Sometimes it is difficult to determine if the lumber used for supports is pressure treated. Generally pressure treated lumber is marked with the type of treatment received at the mill. If the wooden material is not marked, assume that it is not treated. Wood goes beyond lumber; critical materials can be wooden siding or composite materials and these are just as palatable to termites as lumber.

Excessive moisture pooled around wood based materials can also be a condition which leads to termite infestation. Moisture around the foundation of a home might be due to poor grading, bad drainage, or faulty gutters.

Both earth/wood contact and excessive moisture should be corrected to reduce chances of infestation. Homeowners should periodically inspect areas for these defects.

The type of termite which causes the most damage in North America is the subterranean termite. It is important to understand home danger zones for termites. These are areas more likely to be vulnerable to infestation by these termites. Homeowners who understand the home danger zones can take corrective action to reduce chances of infestation by termites.

Since the subterranean termites require ample moisture in order to thrive, areas of proven moisture are more hospitable to these termites. Couple that with a food source which contacts moist areas or the soil, and there are ideal conditions for infestation. In order to reduce the chance of infestation, homeowners can know the home danger zones for termites and can take corrective action so that conditions are not ideal for termites.

Probably the most common danger zone for termites is earth/wood contact. Some people call this moisture to wall contact. This condition is where non-pressure treated wood material is in direct contact with the soil. When this condition is present, there is adequate moisture, adequate food, and adequate protection for the termites. This is a condition conducive to termite infestation. Sometimes it is difficult to determine if the lumber used for supports is pressure treated. Generally pressure treated lumber is marked with the type of treatment received at the mill. If the wooden material is not marked, assume that it is not treated. Wood goes beyond lumber; critical materials can be wooden siding or composite materials and these are just as palatable to termites as lumber.

Excessive moisture pooled around wood based materials can also be a condition which leads to termite infestation. Moisture around the foundation of a home might be due to poor grading, bad drainage, or faulty gutters.

Both earth/wood contact and excessive moisture should be corrected to reduce chances of infestation. Homeowners should periodically inspect areas for these defects.

Pressure treated lumber used in a structure must be “field treated” if cut in the field. That is, if a piece of pressure treated lumber is cut exposing non-treated interior, building codes require that the installer treat the end usually by painting on the product.

Pressure treated lumber must be impervious to decay and insect infestation; however, the guarantee is only for a few years. As the preservative may leach out over the years, the lumber can eventually be essentially the same as untreated wood. Pressure treated lumber is a great material and has much value; however, the homeowner must understand that just because pressure treated or “pretreated” wood was used does not mean that there is permanent protection against insects and decay. Termites can avoid pretreated wood by tunneling over the pretreated wood so that the insects do not contact the treated areas.

While pretreated wood is available in most lumberyards, there are products which contain borates which are less commonly found. Borates are derived from naturally occurring minerals mined in California. Borate pretreated wood is gaining more popularity due to customer preference.

Typically pretreated wood is used as the mudsill or sill plate in termite-prone areas. Also, pretreated wood can be used for joists in close proximity to the soil. Finally, pretreated wood is usually required by code where the wood will contact the soil.

Drywood termites, however, will readily infest furniture, so most infested furniture observed is likely being attacked by drywood termites. The tell tale sign of drywood infestation is drywood termite pellets or small ridged droppings of the color of the wood being attacked. Drywood termite infestation can also occur in furniture which has been transported from regions which have drywood termites and this can lead to an infestation of the structure.

Most infested furniture can be treated by surface treatment provided the product will penetrate into the wood. This treatment will control both subterranean and drywood termites.

Another method is the use of heat. Using this system, the furniture is heated beyond the point where termites can survive. This works well provided that care is taken to make sure that glue joints will not fail. If glue joints fail, the furniture must be reglued. Also, certain types of furniture may have plastics which may distort on heating.

A third method of treatment is fumigation. Fumigation involves the use of penetrating gas lethal to termites. The furniture is typically removed and placed into a container or chamber which can be sealed. An EPA registered gas such as sulfuryl fluoride is introduced and the gas penetrates the furniture, controlling the termites. Special precautions must be taken to make sure that there is no access to the container during fumigation. Special licenses and training are required to fumigate and is not something that a homeowner can do. After the proper time has elapsed, the container is opened to allow air to enter. After it is determined that there is no more fumigant present, the furniture is removed. As the fumigant is a gas, there is no residual in the furniture. Reinfestation is possible.

Direct Wood Treatment works well for both subterranean termites as well as drywood termites. In the case of subterranean termites, the colonies are large and spread out. Sometimes, subterranean termite colonies occupy parts of a house, or multiple houses plus soil areas. Infested wood can be protected and preserved by applying direct wood treatment to the wood. This will control not only termites infesting the wood but will prevent future infestations. Use of a Direct Wood Treatment for subterranean termites is a good but limited application.

Use of a Direct Wood Treatment for drywood termites might be more successful in that drywood colonies are smaller and more compact. If proper inspections are done, infested wood members of a structure or even other wood items such as furniture can be identified. When this is completed, wood treatments can be applied to control drywood termites as well as to further protect the wood from future infestations.

When Direct Wood Treatment technology is used, usually holes are drilled into the wood to allow the control product to get to where the termites are located. If the product is applied under pressure, the product will move through the termite galleries and through natural crevices in the wood. In addition, surface applications may be made, but as a sole method, these products will not penetrate deeply.

Direct wood treatment has a place in an integrated termite control program.

As part of the more formal real estate inspection, the inspector will probe the wood using a long rigid steel tool such as a long screwdriver or specialized tool. Beyond probing, the inspector may “sound” the wood with the butt end of the probing tool or a small hammer or similar device which creates momentum against the wood. This sounding is particularly important in slab foundation constructed homes as there is no access to inspect beneath and baseboards and similar wood components are in close proximity to the soil.

When sounding wood, the inspector will tap along vulnerable areas, listening for solid sounding wood. If the wood sounds “punky” or “hollow” the inspector will scrutinize the area further by probing and perhaps taking moisture readings. If there is no way to ascertain whether there is infestation present, the homeowner may opt to remove the baseboard or molding to examine the area further. Dismantling is not required as part of the inspection and is usually not done by the inspector.

Hollow sounding wood as a sign of termites is common in areas where termite infestation is common. The hollow sound may be from the wood that is destroyed by the termites or softer decayed wood. Also, peculiar sounding wood may be from improper nailing to the studs.

If there is any concern about the hollow sounding wood as potential signs of termite infestation, a professional pest control company should be contacted.

Loose floor tiles as a sign of termites can occur by the additional moisture that termites might introduce into a floor. That moisture might cause the tiles to buckle and heave which can lead to the tiles becoming loose. As the tiles age, the adhesive might not be as strong and the introduction of moisture to the backing may cause the adhesive to fail. When this occurs, even the weight of a person on the tile may cause the tile to shift and become loose. Tiles which become loose by moisture causing a failure of the adhesive are typically soft and pliable such as the vinyl tiles which are placed in place after removing the backer tape during construction. Older tiles which might be parquet wood or laminate wood can swell with moisture and cause them to become loose, either by termite activity or leaks. As termites need moisture, leaks or excessive moisture can lead to termite infestation.

Another instance where loose floor tiles as a sign of termites can be observed is in the case of ceramic or porcelain tile. While it might seem extraordinary for this to occur in such heavy tiles, it is not so much moisture as the culprit but the actual termites. When excessive moisture due to a leak soaks into the subfloor beneath the tiles, termites may find the area and may infest the subfloor. As they consume the wood, there is no adequate support for the entire tile and the tiles may come loose or may wobble. So even ceramic or porcelain tiles are not immune the damaging effects of termites.

Infrared technology has been used for decades. The technology is the same as night vision cameras where heat given off by vehicles or people can be seen. It is also used to find lost people at night by sensing their body heat.

Commercially, infrared cameras detect temperature gradients and these are converted to various colors on an image so that the multi-colored sections depict various temperature ranges. This is particularly helpful when you look at the front of a house, for example, and can see a cooler temperature on the windows which is typical of heat loss due to the glass. But if that temperature gradient drops below the window on the image, there is the possibility of a moisture penetration or even termite tubes which will be cooler due to the moisture. An image will not conclusively denote termite infestation, but it will point to potential issues which require further evaluation.

Infrared cameras are relatively expensive, with many costing over $10,000. If a pest control company uses infrared cameras, they have invested a significant amount of money and may charge additional fees for the use of the camera beyond the normal inspection.

Infrared cameras are excellent tools for specific situations where suspected moisture or even termites must be further evaluated.

There are several types of moisture meters, but the two most common are the pin and the pad moisture meet. A pin type moisture meter is a digital or gauge type of meter which has two sharp pins protruding from the unit. The pins are placed into the substrate to be tested and the reading registers on the gauge. The reading is quick and accurate and the price of the unit is reasonable (less than $200 typically). The disadvantage is that the unit only works with wood and not other building materials and is a surface reading only. It can also leave marks on the surface of the substrate tested.

The pad type of moisture meter is about twice the price of the pin type. The unit has a pad on the back of the unit and the unit is placed on the substrate. Multiple types of materials can be tested including masonry and concrete to see if there is a moisture leak which might soak into wood. There is no damage to the material being tested.

A moisture meter is a valuable tool and some states require that moisture readings be taken as part of an inspection.